1. Field of the Invention
The present invention relates to a communication apparatus and method having the function of transmitting a notification signal while hiding group identification information.
2. Description of the Related Art
A conventional IEEE 802.11b/a/g-based wireless LAN system needs to set the same service set identifier (SSID) in an access point (AP) and a wireless terminal. This setting needs to take account of differences in topology among an ad-hoc mode, an infrastructure mode, and so on. Thus, this setting is suitable for users accustomed to personal computers (PCs) to some extent but is unsuitable for beginners. However, recently, there has been provided a system configured so that a wireless-terminal-side application automatically detects group identifiers (SSIDs) of a plurality of groups and creates a list of connectable access points. As a result, the user is permitted to select an access point, to which an associated wireless terminal is connected, from the list.
Supporting such a wireless LAN system enables automatic establishment of connection to a network, without requiring complicated operations by the user, except for ensuring security utilizing encryption. This development has promoted the growth of a home use market by such a wireless LAN system in recent years.
Also, it is conceivable that a wireless terminal (a malicious third party), which is irrelevant to a user, may attempt an unnecessary access to a group identifier (SSID) made publicly known. Thus, in view of security, access points having a stealth function of intentionally hiding, after confirmation of connection to a desired wireless terminal, a group identifier (SSID) made publicly known to perform automatic detection, have been increased in recent years.
However, to be connected to, or to be accepted by, an access point having the stealth function of intentionally hiding the group identifier (SSID), it is necessary that a user of a wireless terminal preliminarily knows the group identifier (SSID) and individually performs the setting of the SSID. Thus, the user is preliminarily notified of the group identifier (SSID). Therefore, in view of security, leakage of information on the group identifier (SSID) becomes a problem.
Alternatively, an administrator of an access point cancels the stealth function and causes a user to select the group identifier (SSID) of an access point, which is to be accessed, from a list of those of access points that can be accessed. However, according to this method, the administrator of an access point and a user of a wireless terminal are required to perform complicated operations. Also, the convenience of the system is extremely hampered and the usability of the system is degraded.